The specific research interests are: 1) To participate fully in the clinical studies of the CCG by enrolling as many eligible children with primary or recurrent malignant disorders on CCG studies as possible, including Phase I, II and III studies; 2) To continue to provide scientific and administrative expertise to CCG through active participation in Strategy groups, Scientific and Discipline Committees and study committees; 3) To enhance fundamental understanding of biology and treatment of childhood cancer, focusing particularly on the areas of bone marrow transplantation, AML, bone and soft tissue sarcomas, brain tumors, and new agent development; 4) To conduct pilot biologic and therapeutic studies in hematopoietic stem cell transplantation and peripheral blood stem cell support of intensive chemotherapy to provide preliminary data for consideration of these approaches by the CCG.